Machine for knurling or forming teeth in axles



July 2, 1935. c.A. ADAMS ET AL 2,006,332

MACHINE FOR KNURLING OR FORMING TEETH IN AXLES Original Filed Sept. 1'7, 1951 5 Sheets-Sheet l INVENTORS ATTORNLY5.

GOMEF? Ft OWENS jfiu-l m M CHARLES A ADAMS July. 2, 1935. c. A. ADAMS ET AL MACHINE FOR KNURLING OR FORMING TEETH IN AXLES 5 Sheets-Sheet 2 Original Filed Sept. 17, 1931 s mm Z N NDE n w mm NAO T m Hm 06M 6 J xi 6 C. A. ADAMS ET AL MACHINE FOR KNURLING OR FORMING TEETH IN AXLES July 2, 1935.

5 Sheets-Sheet 3 Original Filed Sept. 17, 1951 INVENTORS CHARLE$AADAM5 60%|? EOWENs ATTORNEY! July 2, 1935. c. A. ADAMS ET AL Original Filed Sept. 17, 1951 5 Sheets-Sheet 4 Patented July 2, 1935 I I UNITED STATES PATENT o cE Charles A. Adams, Ellwood City, and Gomer F. Owens, Wayne Township, Pa., assignors to Mathews Conveyor Company, Ellwood City, Pa., a corporation of Pennsylvania Application September 17,1931, Serial No. 563,386

Renewed November 26, 1934 20 Claims. (Cl; 80-5.1)

This invention relates to an improved machine from the magazine into the knurling head, one for knurling or forming teeth in the periphery of at a time, as the latter is rotated, whereby a pora cylindrical body such as an axle or'shaft. tion of the periphery of each axle Will be'knurled,

In the manufacture of various kinds of appaafter which the knurled axle will be discharged ratus as, for example, roller conveyors which from said head onto a suitable receiving means. 5

usually employ shafts or axles having a'nti- A further object is to provide a knurling head friction bearings mounted thereon upon which comprising a fixed body having means rotatably the rollers are supported, it often becomes necesmounted therein and adapted to receive one end sary to provide means for preventing the inner of an axle, and a toothed member being m t ball races or bearing cones from-relatively rotat- Within said head and adapted for relative rotaing upon the axles. Heretofore, it has been'comtion with respect thereto so that when the axle mon practice to fit the bearing cones onto the is conveyed around the axis oi said head, said axles in such a manner that the frictional engagetoothed member will engage-the periphery therement of the bores of the, cones with the axle would of and indent the same in a manner to provide prevent the cones from relativelyrotating therea plurality, of longitudinally extending teeth and 15 on. In some instances, the inner bearing cones grooves in the periphery thereof. have been secured to the axles by means of pins Other objects of the invention reside in the or keys, thereby making it impossible to rotatively particular construction of the knurling head in-' adjust the bearing cones upon the axles when cluding the means for driving the sleeve which no they become worn. Itis desirable that means be receives and feeds the axles one at a time from provided whereby the cones may be rotatively the receiving to the discharging points of the adjusted upon the axles to resent new Wearing h in the means pr vided wit in h h ad f r surfaces to the anti-friction elements of the bear supportin t e a whereby When the latter is ing, when the cones become worn. engaged by the toothed knurling member, the

Roller conveyers usually comprise a plurality a W relatively T011 p a Supporting Surface of fixed axles upon which the rollers are mounted as it travels from the receiving t0 h di h i by means of suitable anti-friction bearings. Ihe p n s o t e a in the means provided for axles, are usuallysupported upon and secured (:0. equally distributing around the circumference of suitable siderails so as to prevent them from, the toothed member, the a resultingfrom the relatively rotating when the rollers are operating. a being n ag d y said t th d m m e n 30 The inner cones of the anti-friction bearings the means provided whereby axles of difierent dimust therefore be mounted upon .the axles in ameters and length ay-b knurled p the such a, manner that they will not rotate thereon ame machine by indexing the machine to anin order to avoid undue wear upon the axle, and other size. knurling head; in the means provided improved machine for forming longitudinally exh same time; and, in the general construction tending teeth in portions of the peripheries of the and arrangement of the parts of the machine. axles adapted to interlockwith correspondingly whereby the Operation of the machine is at y shaped teeth provided in the bores of the inner simplifi d and its rat d u stant a y 4O cones, whereby the latter cannot-relatively rotate automatic.

upon the axles, when in position thereon, but Other objects ofthe invention will appear from whereby they may readily be relatively adjusted th following s t n and a mpanyin thereon to present new wearing surfaces to the drawing and Wi be p d u e annexed anti-friction elements of the bearings, when necclaims. essary, In the accompanying drawings, there has been A furtherobject-is to provide a machine comdisclosed a structure designed to carry out the prising a head having atoothed membermounted various objects of the invention, but it is tobe therein adapted to engage the periphery of an understood that the invention is not confined to axlp and form a plurality f elongated indentathe exact features shownas various changes may tfons and teeth in the periphery thereof, as said be made within the scope of the claims which head is rotated. 3 follow. a

A further object is to provide amachine com- In the drawings: a prising a head having a knurling mechanism Figure 1 is a longitudinal sectional view taken therein, and a magazine adapted to support a onthe line i---! of Figure 2, showing a'machlne 5 plurality of axles, and means for feeding theaxles with a plurality of knurling heads:

it is an object of this invention to provide an whereby both ends of an a e y be l d at 3,5

Figure 2 is a cross sectional view on the line 2--2 of Figure 1; I

.Figure 3 is an enlarged detail sectional view on the line 3--3 of Figure 4 showing the interior Figure 6 is an enlarged detail sectional view showing one end of an axle positioned in the head and a portion of its periphery being knurled;

Figure '7 is a detail view showing the means for,

. disengaging the drive to index the knurling heads;

Figure 8 is a detail sectional view on the line 1 88 of Figure 5;

Figure 9 is a perspective view showing one end of an axle with a portion of its periphery knurled; and

Figure 101s a view similar to Figure 1 but show ing a machine adapted to simultaneously knurl both ends of each axle as they are fed through the machine.

The novelmachine featured in this invention comprises a main supporting shaft 2, preferably tubular in cross-section as shown, and supported in suitable bearing pedestals 3 and 4 secured to suitable base plates 5 mounted upon rails 6-6 as best shown in Figures 1 and 2. T

, Suitable supporting members I and 8 are shown keyed to the supporting shaft 2 adjacent the bearings 3 and 4, and these supporting members support a' plurality of knurling heads A, B, and C, which are adapted to knurl axles of different diametersj. As the knurling headsA, B, and C, are all of like construction with the exception that they aredesigned for knurling axles of different diameters, but one such head will be described in detail, like parts being referred-to by like numerals.

I Each knurling head comprises a body portion 9 preferably cylindrical in cross section and suitably secured to a plate II which, in turn, is secured by suitable bolts I2 to the supporting member I, as best shown inFigure 3. axially alined with the bore I3 in the member "I by suitable means such as indicated at "I4 in Fig ure 3. In like manner, the body portion 9 of the head is axially alined with the plate II by reason ofthe shoulder I 5 provided upon the plate I I. A

; shaft I6 has one end rotatably supported in the bore I3 of the supporting member I and has, its opposite end similarly supported in a bearing I! provided in the supporting member 8.

:The means for driving the shaft I5 is best shown in Figure 1, and comprises a coupling member I8 keyed to the reduced end portion I 9 of said shaft, and having a cylindrical portion 2| adapted to be received in acounterbore 22 provided in a complementary coupling member 23 which is slidably mounted upon a stub shaft 24 of a suitable speed reducer 25.; The reducer 25'is operatively connected toa suitable motor '26 by means of agear drive 21, shown in Figure 2. The coupling member, 23 has a spring-actuated drive pin 28 adapted, to be received in a. socket 29 provided in the coupling member I8 whereby the shaft I6 may be driven by the shaft 24 of the speed reducer; I

' ;Means are provided for disengaging the pin 28 from the clutch member I8 to permit the sup The plate II is porting members 1 and 8 to be rotated about the axis of the main shaft .2,'when it is desired to change from one knurling head to another. Such means is best shown in Figure 7 and comprises a hand lever 3| pivoted to a bracket 32, here shown secured to the frame 'of the speed reducer 2,5. The leved 3| has a yoke 33 carrying a collar 34 provided with lugs 35 received in an annular groove 36 provided in one end of the coupling member 23.1 A suitable spring 31 is coiled about the shaft 24 and constantly urges the coupling -member 23 in a direction towards the coupling member I8. To disengage the pin 28 from the coupling member|8, the clutch lever 3| is moved from the full to the dotted line position shown in Figure "7, whereupon the clutch member 23 will be moved away from the coupling member I8 to thereby move the pin 28 out of the socket 29. When the clutch member 23 is thus positioned, the shaft I6 is out of driving connection with the. speed reducer 25. If desired, the pin 28;may be moved out .of driving engagement with the coupling member I8yby manually moving the pin independently of the coupling member 23. This may be accomplished by means of the head 20 of the bolt. c

The means within the knurling head which engages the periphery of the axle to form the spaced teeth therein is best shown in Figures 3, 4, and 5,

and comprises an external gear 38 suitably secured to the shaft I6 by such means asa key 39. The gear 38 constantly meshes with a plurality of pinions 4| spaced equidistant apart about the circumference of the gear 38 and mounted upon pins 42, each having one end supported in a disk 43 and having their opposite'ends supported in r a disk 44 as best shown in Figure3. The pinions 4| are adapted to roll in an internal ring gear 45 fixedly mounted in the body portion 9' of the head by suitable screws 46.

drical members or shoes 48 secured in position,

therein by suitable bolts'49. Within the mernf bers 48, there is mounted a feeding unit'5l comprising twolparts 52 and' 53 suitably secured togetherby such means as bolts 54. The member 52 has a sleeve 55 formed thereon which is secured at its opposite end to the disk 44, sothat when By thus interposing the pinions 4| between the gears 38'and 45', when the the disks 43 and 44 are rotated; a similar motion will be imparted to the feedingunit 5| comprising the parts 52 and 53. V The sleeve is preferably provided with a suitable bushing 56in which the shaft I6 is received, and a similar bushing 51 may be provided exteriorly ofthe sleeve 55 to provide a suitable bearing for the sleeve in the body portion 9. The feeding unit is shown'provided with oppositely disposed notches or recesses 58adapted to re'ceivethe end portions of the axles which are to be knurled, as will subsequently be described.

An annular recess 59 is'provided between the parts 52 and 53 ofthe feeding unit 5|, asbest shown in Figure 8, which is mounted a toothed knurling' member or wheel 6| here shownse cured to a hub 52 which,fi;n" turn, is secured to the shaft I6 by such means as a pin 63. The toothed'periphery of the wheel 6| projects slightill ly above the bottoms of the recesses 58, provided in the feeding unit 5! so that the teeth on the wheel 6l will indent the periphery of the axles being carried in the notches 58.

A tubular member 64 has one endsuitably secured to the part 53 of the feeding unit 5! and has its opposite end supported upon the shaft It by means of a collar 65 secured to the member 64 as shown in Figure 3. A ring 65 is clamped to the tubular member 64 and has oppositely dis- .posed recesses or notches 6'! adapted to be alined with the notches 58 in the carrier 5 l The notched ring 65 thus cooperates with the feeding unit 5| to support the axles as'they are fed through the knurling head. 7

The means for feeding the axles to the knurling head is best shown in Figures 1 and 2, and comprises'a pair of spaced angle irons 68 having their intermediate portions adjustably supported upon a rod 69 which may be fixedly mounted in suitable uprights 1| supported upon the base plates 5. The lower end ofv the angle iron 68, at the left hand side of the machine when viewed as shown in Figure 1, has a bracket 12 adapted to be attached to a small bracket 13, here shown secured to the periphery of the body portion 9 of the knurling head A. Each knurling head is provided with a similar bracket 13, as shown in Figure 2,to which the bracket 12 of the angle iron 68 at the left hand side of the machine may be attached, depending upon which knurling head is to be used. The angle iron 68 at the right hand side of the machine has a similar bracket [2 adapted to be detachably connected to a spider 14. The spider I4 is provided with a feather key 15 adapted to slide in a keyway "i6 provided in the shaft 2, whereby the spider may be axially adjusted upon the shaft 2, so as to space the angle irons 68 the proper distance apart to suit the lengths of the axles to be knurled. Suitable means, not shown, are providedfor locking the spider 14 to the shaft 2. The angle irons sa-sc thus cooperate to provide a magazine for supporting the unknurled axles, as shown in Figure 2. 1 7

Radial slots 16 are provided in one end of the body portion'9 of each knurling head, as shown in Figure 5. These slots register with the gaps provided between the ends of thesemi-circular members 48, and the bottoms of these slots are substantially alined with the bottom of the counterbore 41 which, it will be noted by reference to Figures land 2, is substantially alined with the upright flange of the angle irons 68.

Suitable rails 11 are provided at the opposite side of the knurling head adapted to receive the knurled axles, as best shown in Figure 2.

When a plurality of knurling heads are provided in a single machine, as shown in Figures 1 and 2, means are provided for locking each knurling head and its associated partsin'alinement with the drive shaft 24 of the speed reducer 25, and also whereby the slots 16 of a selected knurling head may be alined with the discharge ends of the angle iron rails 68 as shown in Figure 2.

Such means is shown in Figures 1 and 2, and may consist of a pair of dogs 18 slidably mounted in brackets 19 and each having an operating arm 8i pivotally connected therewith. These arms are secured to a rock shaft 82 mounted in suitable bearings provided upon the brackets 19. The supporting members 1 and 8 secured to the main supporting shaft 2 are preferably triangular in shape as shown in Figure 2, and are'provided at their outer extremities with a plurality of notches 83 adapted to receive the terminals of the dogs 78 as clearly shown in Figure 2. Springs 84 constantly urge the dogs '18 in a direction to engage the notches or recesses 83 provided in the sup: porting members i and 8.

A suitable foot pedal 85 is secured to the rock shaft 82 whereby the latter may be actuated to move the dogs out of locking engagement with the members i and B. When the dogs are moved out of engagement with their respective notches 83 and the pin of the clutch member 23 is moved out of engagement with'the clutch member 18 of the knurling head alined with the drive shaft 24, the main supporting shaft 2 may be rotated to move a selected knurling head into alinement with the drive shaft 24, said head being locked in such position by means of the dogs l8engaging the notches 83 in the supporting members 1 and 8.

In the operation of this novel knurling machine, the selected knurling head is alined with the drive shaft 24 of the speed reducer 25 and is locked in such position by means of the dogs 18;

The shaft l6 of the selected knurling head is then operatively connected with the drive shaft 24 of the speed reducer 25 by means of the coupling members it and E3. The rail 68 at the right hand side of the machine, when viewed as shown in Figure l is then relatively adjusted upon the supporting rod 69 so that the spacing between the upright flanges of the two rails 68 may be slightly greater than the overall lengths of the shafts to be knurled. e

The shafts to be knurled are thenplaced in the magazine formed by the rails 63, as shown in Figure 2, whereby some of the axles will enter the slot positioned at the upper right hand portion of the knurling head, when viewed as shown in Figure .2, so that the lower axle will be positioned in the notches provided in the carrier 5|, one end of the axle being supported in the notch 58 of the feeding unit 5| and the opposite end of the axle being supported in one of the notches 61 of the ring 6 6, as indicated in dotted lines in Figure 3. As the shaft it of the knurling head is rotated;

the external gear 38 secured to this shaft will cause the pinions ll to roll around in the internal ring gear 45, whereby the driving disks 43 and 44 will be rotated at a relatively slower speed than the gear 38, whereby a similar motion will be imparted to the sleeve and therefore the feeding unit 5| including the ring member 56, which rotates as a unit with the feeding unit 5| because of the tubular member M being secured to the part 53 of the feeding unit. The collar at the end of the member M rotates upon the shaft 16. Such rotation of the feeding unit will permit the axle positioned in the notches 58 and 67 of the feeding unit to be conveyed from the magazine around the axis of the shaft it until it reaches the slot 76 diametrically opposite, whereupon the knurled axle will be discharged from the head onto the receiving rails Tl.

The knurling of the axle is effected by the teeth of the knurling wheelfiil engaging and indenting that portion of the peripheral surface thereof alined with the knurling wheel 6i, and because of the peripheral speed of the knurling wheel being relatively greater than the speed of the feeding unit 5%, thereby causing the axle be-' ing knurled to constantly rotate in the notch 58 in the knurling headas itis being carried from the receiving slot 76 adjacent to the' magazine;-

around to the' discharge slot provided at the re ceiving rails 17.

During movement of the shaftber89 upon the supporting shaftZ. .Thusfby from the receiving to the discharge slots, it will roll upon the inner surface 86 of one of the semicircular members Ali-,the latter being relieved at their intermediate portions, as shown at 81 in Figure 3 to provide clearance for the teeth 88 being formed in the periphery of the axle. (See Figure 9.) By thus forming the teeth in the periphery of the axle, the latterv will not be weakened as no material is cut away, the material of the periphery of the axle merely being upset by pressure to form the teeth as shown.

Because of the knurling wheel being driven, as

7 herein before described, the teeth, formed in the feeding unit. Thus,

lar to the one illustrated in Figures 1 and 2, but I periphery of the axle will be accurately spaced, so that bearing coneshaving their bores provided with correspondingly shaped teeth may be readily fitted onto the axle and interlocked therewith to prevent relative rotation of the bearing cones thereon. Also, by providing correspondingly shaped teeth on the periphery of the axle and in the bore of the bearing cone, the latter may readily be rotatively adjusted upon the axle by simply moving it out of engagement with the teeth 88 thereof and relatively rotating it upon the axle, and then again moving it into interlocking engagement with the teeth 88 of the axle. i

The machine is automatic in operation, it being only necessary to keep the magazine rails 68 supplied with unknurled axles. Because of the feeding unitbeing provided with two notches 58, as shown in Figure 5, as soon as oneaxle has been knurled and is discharged from one of the notches on the feeding unit onto the receiving rails W,

the notch at the opposite side .of the feeding unit will be alined with the magazine whereby another unknurled axle will be delivered to the only one axle is being knurled at a time. During the period that an axle'is being knurled, ,the following unknurled axle will be supported upon the peripheries of the parts 52 and 53 of the feeding unit 5|, as will readily be understood by reference to Figure 1, and as indicated by the dotted lines in Figure 5. Also, because of the differences in diameters of the gears 38 and 45, the periphery of the knurling wheel 5| will constantly change its position with respect to the notches 58 so that all of the,

teeth in the knurling wheel will be used an equal amount in the operation of knurling a plurality of axles, thereby evenly distributing the wear over all of its teeth. By providing the machine with three knurling heads, axles of different diameters may be knurled upon the same machine, thereby economizing in space and, at the same time, mak- 1 ing a very compact and efficient machine.

. Figure illustrates a knurling machine simihaving two knurling heads mounted upon each shaft 16, whereby both ends of each axle may be knurled at the same time. 'In the construction here shown, the knurling heads on each shaft l6 are made right and left hand and are arranged as shown. The head at the right hand side of the machine is mounted for longitudinal adjustment upon the shaft l5 and is supported upon a member 89 adjustably secured to the main supporting shaft 2 by means of a threaded rod 9| mounted in the supporting members 1 and 8, and having a threaded connection with the member 89. One end of the rod 9| is held against longitudinal movement in the supporting member,1,'while the opposite end portion 92 thereof is preferably squared to receive a suitable wrench or other instrument whereby the rod may be rotated to longitudinally translate the mem- The member 89 is provided with a feather key 93 slidable in the keyway provided in the shaft 2. This feather key prevents the member 89 from relatively rotating upon the main shaft 2 and thus assures that each pair of knurling' heads will always be axially alined with each other. In the construction shown inFigure 10, the magazine rail 68 at the right hand side of the machine is supported in a manner similar to the rail 68 at the opposite end of the machine, each knurling head at 'the right hand side of the machine being provided with a bracket 13 similar to the corresponding brackets provided on the knurling heads provided at the left hand side of the machine.

- In the drawings and specification, we have shown and described the machine as being an independent machine adapted for use onlyto knurl axles or similar devices. It is to be understood, however, that in some instances, it may be desirable to use only a single knurling head which may be provided with means for supporting it upon the bed of an ordinary lathe and then connecting the shaft IE to the head of thelathe.

and chain or gearing is considered to be a posi- I tive drive, whereas a. friction drive is not considered to be a positive drive within this definition.

We claim as our invention: f

1. In a machine of the class described, a fixed head having a feeding unit mounted therein and adapted to receive one end of an element to be knurled, a toothed member mounted within said head'and adapted for relative rotationtherein, and toothed-means for operating said feeding unit at a relatively slower speed than said member whereby said toothed member will engage and indent a portion of the periphery of said ele: ment and form a plurality of teeth therein spaced equidistant apart. 1

2. Ina machine of the class described, a head having. a feeding unit mounted therein and adapted to receive one end of an element to be knurled, an annular toothed; member mounted within said head and adaptedfor relative rotation therein, and a positive drive for operating said feeding unit at a relatively slower speed than said toothed member and in the same direction, thereby causing the toothed member to engage and relatively rotate the'element in said supshaft, said feedingunit having a notch in its periphery for supporting an axle in position to engage the perihpery' of said toothed member whereby said member will indent and upset a portion of the peripheryof the axle to provide be knurled, gear means on said shaft for driving said feeding unit in the same direction as the shaft but at a relatively slower speed, a knurling wheel secured to the shaft and having its toothed periphery arranged to engage a portion ofv the periphery of an axle supported in the'notch in said feeding unit, and means within said head for holding the axle in said notch during rotation of the feeding unit whereby when said parts are operated, said knurling wheel will engage and upset a portion of the periphery of said axle around the circumference thereof and form a plurality of longitudinally extending teeth there in, spaced equidistant apart.

5, In a machine of the class described, a head having a shaft rotatably mounted therein and provided atone end with a counterbore, a feeding unit movably mounted within said counterbore and having notches in the periphery thereof for receiving axles 'to be knurled, means on said shaft for driving said feeding unit in a corresponding direction of rotation but at a relatively slower speed, a knurling wheel secured to the shaft and having its toothed periphery projecting above the bottoms of the notches in said feeding unit and adapted to engage the periphery of an axle supported in one of said slots, and

members fitted in said counterbore and .ar-'

ranged to retain the axles infsaid notches whereby when said parts are operated, said knurling wheel will engage the portions of the peripheries of .said axles supported-in said notches, whereby a plurality of longitudinally extending teeth are formed therein, spaced equidistant apart.

6. A knurling machine comprising a head provided with a suitable support, a shaft rotatably mounted in said head, an external gear keyed to the shaft, an internal gear secured in said head, a plurality of pinions operatively connecting together said gears, a feeding unit operatively connec'tedwith said pinions'and having means adapted to support one end of an axle to be knurled, a knurling wheel secured to said shaft and having its periphery 'positioned to engage an axle supported in said feeding unit, and means for driving said-shaft whereby said knurling wheel will engage and indent a portion of the peripheryof the axle and, at the same time,

cause said axle to be relatively rotated in said feeding unit whereby a plurality of equally spaced teeth will be formed in the periphery of the axle around its circumference.

7. A knurling machine comprising a head having a shaft rotatably mounted therein, a feeding unit having notches in its peripheryeach adapted to support one end of an axle to be knurled,

said feeding unit having an annular recess therein, a knurling wheel mounted within said recess and secured to said shaft and having its periphery projecting above the bottoms of said notches and adapted to engage axles supported therein, a gear mechanism within said head .operatively connecting said feeding unit with said shaft and adapted to rotate the feeding unit in I the same direction but at a relatively-slower speed whereby said knurling wheel-will cause the axles in said notches tobe rotatedtherein and thereby indent a portion of the peripheryof the axle whereby a plurality of equally spaced-teeth will be formed in the periphery of the axle around its circumference. 1

8. A knurling machine comprising a head pro- I vided with a suitable support, a shaft rotatably mounted in said head, an external gear keyed to the shaft, an internal gear secured in said head, a plurality of pinions operatively'connecting to ge ther said gears, a feeding unit operatively connected with said pinions and adapted to Support one end-of an axle to'be knurled, said feeding unit having an annular recess therein, a knurling wheel mounted within said recess and secured to said shaft and having its periphery positioned to engage an axle supported in said feeding unit,;and meansfor driving said shaft whereby said-pinions will be operated to rotate said feeding unit at a relatively slower speedthan the speed of said shaft, and whereby said knurling wheel will be rotatedsynchronously with said shaft and thereby engage and indent a portion 'of the periphery of the axle and, at-the same time, cause said axle to berelatively rotated in said feeding unit whereby a plurality of equally spaced teethwill be formed in the periphery of the axle'around its circumference I =9. In a machine of the class described,"a plu-' rality of knurling heads, a support for said heads mounted for rotary adjustment, whereby a selected head may be positionedtoreceive axles to-be knurled, means within each head for knurling a portion of the periphery of an axle, means for.

feeding the axles to the selected'he'ad, and means for operating the knurling'mechanism in the said head, whereby an axle fed thereto will :be knurled and discharged from the head onto a suitable receiving means. i

10. A knurling machine comprising a shaft, a plurality of knurling heads suitably supported upon said shaft and each adapted tojknurl a different sized axle, means for locking said shaft in an adjusted position whereby a selected knurling head may be positioned to receive axles to be knurled, and an operating mechanism for actuating the knurling mechanisms of said heads, said operating'mechanism being commonto all of said heads.

11. A knurling machine comprising a main shaft, a plurality of knurling heads suitably supported upon said shaft and each adapted to knurl a different sized axle, means for locking said shaft in an adjusted position whereby a selected knurling head may be positioned to receive axles to be knurled, an operating mechanism for v actuating the knurling mechanisms of said heads,and,

means for feeding the axles tothe knurlingmechanism of the selected head, one at a time. 1

12. A knurling machine comprising a main shaft having a supporting member mounted at each end thereof, a plurality of shafts mounted in said supporting members and spaced equidistant apartand each supporting a knurling head, said heads being adapted to knurl shafts of different diameters, a knurling mechanism in each head, a lock for securing said supporting members in adjusted position whereby a selected knurling head may be positioned to receive axles to be knurled, a common driving mechanism for said knurling heads, and means for operatively connecting the selected knurling head with said driving mechanism.

7 he bers' l3; A- knurling machine comprising a -main shaft having a supporting member mounted at each-endthereof, a plurality of shafts mounted in said supporting members and spaced equidistant apart and each supporting a. knurling head,

said heads being adapted to knurl shafts of different diameters, a knurling mechanism in each lockfor securing said supporting memadjusted position whereby a selected knurlinghead may be positioned to receive axles to be knurled, means for feeding the unknurled axles to the selected head, and a driving mechanism for said knurling heads. 14. A knurling machine comprising a main shaft having a supporting member mounted at each :end thereof, a plurality of shafts mounted.

' unknurled axles to the selected head, one at a time, and a common driving mechanism for said heads comprising means for operatively connectingit with the selected knurling head.

15; In a 'machineof the class described, a drive shaft, a toothed member secured to said shaft, a feeding unit adapted to receive an element to be indented and feed it into. engagement with the toothed periphery of said member, whereby its. surface will be indented, and

apositive driving connection between said shaft and said feeding unit by which the latter will ,be positively driven at a predetermined slower speed thanv said toothed member to thereby cause the indentures impressed in the surface of said element to be spaced equi-distant apart around the entire circumference thereof.

16.1n a machine of the class described, a drive shaft, a toothed member secured thereto for direct rotation therewith, a feeding unit adaptedto receive an element to be indented and feed itinto engagement with the toothed periphery of said member, whereby its surface will be indented, and a gear driveoperatively connecting said feeding unit to said shaft adapted to drive the feeding unit in the same direction as said member, but at a relatively slower speed, whereby the element will be relatively rotated in said feeding'unit to cause a portion of its periphery to be indented around the entire circumference thereof.

' 17.1n a machine of the class described, a head having a feeding unit mounted therein and provided with one'endof an element to be knurled, a member concentrically mounted within said head and notch adapted to receive having a toothed periphery projecting above thebottom of said notch, means within said head for retaining the element in said notch whereby said toothed member may engage and indent a portion of the periphery of said element and form a plurality of longitudinally extending teeth or serrations in its periphery, and a gear drive for operating said feeding unit at a relatively slower speed than said toothed members and maintaining a predetermined speed ratio between the feeding unit and said toothed member.

18. In a machine of the class described, a head having a feeding unit mounted for rotation therein, a toothed member mounted within said feeding unit and adapted for relative rotation with respect thereto, said feeding unit having means for supporting an axle in position to engage the periphery of said toothed member whereby said member will indent and upset a portion of the periphery of the axle to form a plurality of longitudinally extending teeth spaced equidistant apart, and positive means for maintaining a. predetermined speed ratio between the feeding unit and said toothed member. v

19. In a machine of the class described, a head having a shaft mounted therein, a feeding unitalso mounted in said head and operatively connected with said shaft, a toothed member within the feeding unit and secured to the shaft for direct rotation therewith, and said feeding unit having notches therein for supporting an axle in position to engage the periphery of said toothed member whereby said member will indent and upset a portion of the periphery of the axle to provide a plurality of longitudinally extending teeth spaced equidistant apart around the circumference of theaxle, and positive means for maintaining a predetermined speed ratio between the feeding unit and said toothed member.

20, In a machine of the class described, ahead provided with a suitable support, a shaft rotatably mounted in said head, a feeding unit movably mounted within the head and having means for receiving an axle to be knurled, a knurling wheel secured to the shaft and having its toothed periphery arranged to engage a portion of the periphery of an axle supported in said feeding unit-whereby when said'parts are operated, said knurling wheel will engage and upset a portion of the periphery of said axle around its circumference and form a plurality of longitudinally-extending teeth therein spaced equidistantly apart, and a gear mechanism; for

driving the feeding unit at a relatively slower speed than said knurling wheel. v

CHARLES A.. ADAMS. GOMIER F. OWENS. 

